Most Recent Weekly Report: 30 April-6 May 2008

Based on information from RVO, the Darwin VAAC reported that Balbi erupted on 7 May. Ash was not detected on satellite imagery. [Correction: RVO later confirmed that Balbi did not erupt on 7 May and attributed the reports to thunderstorm activity.]

Most Recent Bulletin Report: August 1995 (BGVN 20:08)

Profuse steaming from the summit amphitheater

Aerial inspection was carried out on 22 August, after the 16 August, M 7.8 earthquake that struck 100 km to the W. The inspection revealed profuse white vapor coming from large-output fumaroles in the main fumarole field of the stratovolcano's summit amphitheater. In contrast, emissions at Crater B were moderate and from diffused sources.

Recent landslides were noted in two of the summit craters. The more extensive slides were on the W wall of Crater B. These landslides were thought to have been caused by shaking during the 16 August earthquake.

In general, the visible activity at Balbi appeared to be similar to that observed during previous inspections in the late 1980's. However, emissions may have been more voluminous in 1995.

Balbi marks the highest point on Bougainville Island, forming a summit composed of coalesced cones and lava domes and hosting a large solfatera field. Interviews with local inhabitants suggested that Balbi's last eruption took the lives of a number of people in about 1800-1850.

Information Contacts:Patrice de Saint-Ours and Ben Talai, RVO.

Index of Weekly Reports

Weekly Reports

30 April-6 May 2008

Based on information from RVO, the Darwin VAAC reported that Balbi erupted on 7 May. Ash was not detected on satellite imagery. [Correction: RVO later confirmed that Balbi did not erupt on 7 May and attributed the reports to thunderstorm activity.]

Bulletin Reports

All information contained in these reports is preliminary and subject to change.

10/1984 (SEAN 09:10)Boiling mud, active fumaroles and solfataras

Balbi, Bougainville's highest point, is in the N-central part of the island on the axial volcanic chain. In [what is possibly an eroded caldera at the summit of the composite cone, seven craters] lie on a N-S ridge about 3 km long. [There are also two cones about 2 km W of the line of craters.] Only Crater B, about 600 m in diameter and second from the S, shows activity. Anthropological evidence suggests an explosive eruption accompanied by nuées ardentes and fatalities, sometime between 1800 and 1850 [but recent geological work does not support this.]

"A boiling mud pool and up to a dozen large, very active fumaroles flanked the lineament of craters. Large collapses have occured into Crater B, and further extensive tension cracks were visible around the crater's rim. Many small solfataras were still active in the W wall of Crater B. The lake in Crater C had diminished in size." [Recent RVO investigations show that the fumaroles are aligned orthogonally to the 7-crater lineament and that the mud pool is no longer active.]

"A brief aerial inspection of Balbi was made on the 27th. No changes were noted. Voluminous white emissions continued from the 1-km-long fumarole field in the NE part of the summit amphitheatre, and from sources in one of the summit craters (Crater B)."

Aerial inspection was carried out on 22 August, after the 16 August, M 7.8 earthquake that struck 100 km to the W. The inspection revealed profuse white vapor coming from large-output fumaroles in the main fumarole field of the stratovolcano's summit amphitheater. In contrast, emissions at Crater B were moderate and from diffused sources.

Recent landslides were noted in two of the summit craters. The more extensive slides were on the W wall of Crater B. These landslides were thought to have been caused by shaking during the 16 August earthquake.

In general, the visible activity at Balbi appeared to be similar to that observed during previous inspections in the late 1980's. However, emissions may have been more voluminous in 1995.

Balbi marks the highest point on Bougainville Island, forming a summit composed of coalesced cones and lava domes and hosting a large solfatera field. Interviews with local inhabitants suggested that Balbi's last eruption took the lives of a number of people in about 1800-1850.

The large Balbi stratovolcano forms the highest point on Bougainville Island. The 2715-m-high summit of the complex andesitic volcano is part of a large number of coalesced cones and lava domes. Five well-preserved craters occupy a NW-SE-trending ridge north of the summit cone, which also contains a crater. Three large valleys with steep headwalls dissect the flanks of the volcano. The age of the most recent eruption of Balbi volcano is not known precisely. An oral tradition of a major eruption during the 19th century is now thought to be in error, but could refer to minor eruptive activity from this relatively youthful-looking volcano. Fumaroles ares located within 600-m-wide Crater B and on its western flank.

The Global Volcanism Program has no synonyms or subfeatures listed for Balbi.

The broad, complex Mount Balbi stratovolcano is seen here in profile from the village of Wakunai, east of the volcano along the NE coast of Bougainville Island. Balbi, the highest and largest-volume volcano on the island, has an elongated profile resulting from the formation of a NW-SE-trending chain of volcanic vents. The age of the most recent eruption of Balbi volcano is not known precisely. An oral tradition of a major eruption during the 19th century is now thought to be in error, but could refer to minor eruptive activity.

Photo by Wally Johnson, 1987 (Australia Bureau of Mineral Resources).

The massive Balbi stratovolcano forms the highest point on Bougainville Island. The 2715-m summit of the complex volcano is part of a large number of coalesced cones and lava domes. Five well-preserved craters occupy a NW-SE-trending ridge north of the summit of the volcano, which also contains a crater. Crater C, containing a small lake, is seen here from the east. Steam from a fumarole field on the western flank of 600-m-wide Crater B is visible at the left. The latest eruption of Balbi may have been as recent as the mid-19th century.

Photo by Wally Johnson, 1987 (Australia Bureau of Mineral Resources).

Much of the left side of this NASA image with north to the upper left is covered by volcanic products from Tore volcano in the Emperor Range on NW Bougainville Island. The Tore massif lies to the left of the light-colored area at the center of the image, Balbi volcano. Two Pleistocene ignimbrites from Tore formed a broad fan that extends the coastline to the west (lower left). The dark-colored caldera lake of Billy Mitchell volcano is at the right, above an ash plume originating from Bagana volcano.

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.

EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).